Proof-of-concept for identifier rewriting via walk API

2 files changed, 34 insertions, 8 deletions

diff --git a/compiler/types.scm b/compiler/types.scm
index 07ac912..e73e932 100644
--- a/compiler/types.scm
+++ b/compiler/types.scm
@@ -47,6 +47,7 @@
             ι-body-conjunction
 
             make-reference
+            <reference>
             reference?
             reference-parts
 
diff --git a/compiler/walk.scm b/compiler/walk.scm
index f1d567c..dabd438 100644
--- a/compiler/walk.scm
+++ b/compiler/walk.scm
@@ -106,11 +106,36 @@
 
 (define (mutate-tree policy f)
   (define (recur form)
-    (cond ((list? form) _)
-          ((constant? form) _)
-          ((set-literal? form) _)
-          ((object-literal? form) _)
-          ((reference? form) _)
-          ((variable-ref? form) _)
-          (else _)))
-  (map recur (policy-rules policy)))
+    (match form
+      ((x xs ...)
+       (map (lambda (x) (f (recur x))) (cons x xs)))
+
+      ;; TODO: Should this include the `head' of a rule too?
+      (($ <rule> default head body)
+       (f (make-rule default head (recur body))))
+      (($ <body> conjunction)
+       (f (make-body (recur conjunction))))
+      (($ <for-all> domain key value body)
+       (f (make-for-all domain key value (recur body))))
+      (($ <comprehension> kind key value body)
+       (f (make-comprehension kind key value (recur body))))
+
+      (($ <reference> parts)
+       (f (make-reference (recur parts))))
+      (anything-else (f anything-else))))
+  (make-policy
+   (policy-package policy)
+   (policy-imports policy)
+   (zip (map car (policy-rules policy))
+        (map (compose recur cadr) (policy-rules policy)))
+   (policy-comments policy)))
+
+(define (my-rewrite-anonymous form)
+  (match form
+    (($ <variable-ref> name)
+     (make-variable-ref
+      (if (string= name "$0")
+          "anony_0"
+          name)))
+    (anything-else
+     anything-else)))